def sum(number_one, number_two):
    number_one_int = convert_int(number_one)
    number_two_int = convert_int(number_two)
    
    result = number_one_int + number_two_int
    return result

def convert_int(number_string):
    converted_int = int(number_string)
    return converted_int

answer = sum('1', '2')